114
FXUS63 KDLH 180523
AFDDLH
Area Forecast Discussion
National Weather Service Duluth MN
1223 AM CDT Sun Mar 18 2018
.SHORT TERM...(This evening through Sunday)
Issued at 212 PM CDT Sat Mar 17 2018
High pressure will gradually build eastward into portions of the
Central Great Lakes by Sunday Night, while an inverted trough
develops over the Central Dakotas due to a developing Colorado
Low. This will increase cloud cover from west to east late tonight
through Sunday. Slowed down the timing of increasing cloud cover
compared to the previous forecast package. This will allow for strong
radiational cooling before clouds move in, so overnight lows are a
few degrees cooler than the previous forecast. Lows range from
the teens across Inland locations, to the low to mid 20s along
the Lake Superior Shoreline.
Expect more clouds than sunshine across much of the Northland on
Sunday. Increased precipitation chances along the International
Border as high resolution guidance (NAM/ARW/NMM) show a subtle
shortwave ejecting from southern Manitoba into western Ontario on
Sunday. Suspect the ARW/NMM guidance are a bit too high on QPF,
and develop more vigorous and widespread shower activity than
currently anticipate. With the increased cloud cover, expect
cooler temperatures in comparison to today, but it still will be 5
to 10 degrees warmer than normal. Highs range from the 30s in the
Minnesota Arrowhead, to the 40s elsewhere.
.LONG TERM...(Sunday night through Saturday)
Issued at 212 PM CDT Sat Mar 17 2018
Quiet through much of the extended with temperatures near to below
normal at the start of the week, but warming to a few degrees
above normal by the end of the week.
Initially in the extended, a subtle shortwave will move across
Ontario Sunday night into early Monday. This will bring low
chances of snow and freezing drizzle along the International
Border. Flow will become northeasterly off of Lake Superior, and
with Lake Surface to 850 hPa temperature differences around 10
degrees, anticipate some light lake effect snow showers or
flurries along portions of the North and South Shore of Lake
Superior. The Colorado Low previously mentioned will eject into
the Lower Mississippi River Valley on Monday, while the inverted
trough over the Dakotas slides eastward. This will bring low
chances of precipitation across the Brainerd Lakes to the
International Falls area Monday afternoon. Highs on Monday range
from the mid to upper 20s across the Minnesota Arrowhead, to the
30s elsewhere.
A shortwave will dig from Saskatchewan late on Monday into the
Northern Plains by Tuesday. This will interact with the inverted
trough and develop a broad low across the Upper Mississippi River
Valley on Tuesday. This feature will slide southeastward into the
Central Great Lakes on Wednesday. Expect chances of light snow
across parts of northeast Minnesota on Tuesday into early
Wednesday. Highs on Tuesday will be near normal with readings
ranging from the mid 20s to mid 30s.
High pressure will build into the Upper Mississippi River Valley
late on Wednesday and into Thursday as a ridge slides into the
Northern Plains. The forecast becomes uncertain late in the week
as guidance is all over the place with next wave digging in from
the Pacific Northwest. The GFS is the quickest solution at the
moment, breaking down the ridge over the Upper Midwest and
ejecting a trough into the Northern Plains. This develops a low in
the High Plains early on Friday and moves eastward into the Mid
Mississippi River Valley on Friday. The ECMWF/GEM solutions are
much weaker and slower with the trough moving in. These pieces of
guidance develop a low in nearly the same area, but about 12 hours
later. Regardless, anticipate increasing chances of precipitation
on Friday and Saturday. Expect the mildest readings of the
extended on Friday with highs ranging from the mid 30s to the mid
40s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1223 AM CDT Sun Mar 18 2018
High pressure will gradually lose it`s grip on the
Northland weather throughout the period, although skies will remain
mostly clear overnight. A weak trough moving out of the Dakotas,
along with a backdoor cold front moving southwest across the CWA
will result in an increase of mid and low level clouds on Sunday. As
a result, we could see areas of MVFR CIG`s, developing from west to
east on Sunday, and continuing into Sunday evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 22 40 19 31 / 10 10 10 10
INL 17 40 15 33 / 10 20 20 0
BRD 18 43 22 36 / 0 10 10 10
HYR 17 46 21 36 / 0 0 10 0
ASX 22 40 18 31 / 0 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
SHORT TERM...WL
LONG TERM...WL
AVIATION...Melde/DAP